{"cve":"CVE-2022-49059","nvd":{"published":"2025-02-26T07:00:43.150","modified":"2026-06-17T05:16:57.833","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfc: nci: add flush_workqueue to prevent uaf\n\nOur detector found a concurrent use-after-free bug when detaching an\nNCI device. The main reason for this bug is the unexpected scheduling\nbetween the used delayed mechanism (timer and workqueue).\n\nThe race can be demonstrated below:\n\nThread-1 Thread-2\n | nci_dev_up()\n | nci_open_device()\n | __nci_request(nci_reset_req)\n | nci_send_cmd\n | queue_work(cmd_work)\nnci_unregister_device() |\n nci_close_device() | ...\n del_timer_sync(cmd_timer)[1] |\n... | Worker\nnci_free_device() | nci_cmd_work()\n kfree(ndev)[3] | mod_timer(cmd_timer)[2]\n\nIn short, the cleanup routine thought that the cmd_timer has already\nbeen detached by [1] but the mod_timer can re-attach the timer [2], even\nit is already released [3], resulting in UAF.\n\nThis UAF is easy to trigger, crash trace by POC is like below\n\n[ 66.703713] ==================================================================\n[ 66.703974] BUG: KASAN: use-after-free in enqueue_timer+0x448/0x490\n[ 66.703974] Write of size 8 at addr ffff888009fb7058 by task kworker/u4:1/33\n[ 66.703974]\n[ 66.703974] CPU: 1 PID: 33 Comm: kworker/u4:1 Not tainted 5.18.0-rc2 #5\n[ 66.703974] Workqueue: nfc2_nci_cmd_wq nci_cmd_work\n[ 66.703974] Call Trace:\n[ 66.703974] \n[ 66.703974] dump_stack_lvl+0x57/0x7d\n[ 66.703974] print_report.cold+0x5e/0x5db\n[ 66.703974] ? enqueue_timer+0x448/0x490\n[ 66.703974] kasan_report+0xbe/0x1c0\n[ 66.703974] ? enqueue_timer+0x448/0x490\n[ 66.703974] enqueue_timer+0x448/0x490\n[ 66.703974] __mod_timer+0x5e6/0xb80\n[ 66.703974] ? mark_held_locks+0x9e/0xe0\n[ 66.703974] ? try_to_del_timer_sync+0xf0/0xf0\n[ 66.703974] ? lockdep_hardirqs_on_prepare+0x17b/0x410\n[ 66.703974] ? queue_work_on+0x61/0x80\n[ 66.703974] ? lockdep_hardirqs_on+0xbf/0x130\n[ 66.703974] process_one_work+0x8bb/0x1510\n[ 66.703974] ? lockdep_hardirqs_on_prepare+0x410/0x410\n[ 66.703974] ? pwq_dec_nr_in_flight+0x230/0x230\n[ 66.703974] ? rwlock_bug.part.0+0x90/0x90\n[ 66.703974] ? _raw_spin_lock_irq+0x41/0x50\n[ 66.703974] worker_thread+0x575/0x1190\n[ 66.703974] ? process_one_work+0x1510/0x1510\n[ 66.703974] kthread+0x2a0/0x340\n[ 66.703974] ? kthread_complete_and_exit+0x20/0x20\n[ 66.703974] ret_from_fork+0x22/0x30\n[ 66.703974] \n[ 66.703974]\n[ 66.703974] Allocated by task 267:\n[ 66.703974] kasan_save_stack+0x1e/0x40\n[ 66.703974] __kasan_kmalloc+0x81/0xa0\n[ 66.703974] nci_allocate_device+0xd3/0x390\n[ 66.703974] nfcmrvl_nci_register_dev+0x183/0x2c0\n[ 66.703974] nfcmrvl_nci_uart_open+0xf2/0x1dd\n[ 66.703974] nci_uart_tty_ioctl+0x2c3/0x4a0\n[ 66.703974] tty_ioctl+0x764/0x1310\n[ 66.703974] __x64_sys_ioctl+0x122/0x190\n[ 66.703974] do_syscall_64+0x3b/0x90\n[ 66.703974] entry_SYSCALL_64_after_hwframe+0x44/0xae\n[ 66.703974]\n[ 66.703974] Freed by task 406:\n[ 66.703974] kasan_save_stack+0x1e/0x40\n[ 66.703974] kasan_set_track+0x21/0x30\n[ 66.703974] kasan_set_free_info+0x20/0x30\n[ 66.703974] __kasan_slab_free+0x108/0x170\n[ 66.703974] kfree+0xb0/0x330\n[ 66.703974] nfcmrvl_nci_unregister_dev+0x90/0xd0\n[ 66.703974] nci_uart_tty_close+0xdf/0x180\n[ 66.703974] tty_ldisc_kill+0x73/0x110\n[ 66.703974] tty_ldisc_hangup+0x281/0x5b0\n[ 66.703974] __tty_hangup.part.0+0x431/0x890\n[ 66.703974] tty_release+0x3a8/0xc80\n[ 66.703974] __fput+0x1f0/0x8c0\n[ 66.703974] task_work_run+0xc9/0x170\n[ 66.703974] exit_to_user_mode_prepare+0x194/0x1a0\n[ 66.703974] syscall_exit_to_user_mode+0x19/0x50\n[ 66.703974] do_syscall_64+0x48/0x90\n[ 66.703974] entry_SYSCALL_64_after_hwframe+0x44/0x\n---truncated---","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-416"],"references":["https://git.kernel.org/stable/c/1a1748d0dd0f0a98535c6baeef671c8722107639","https://git.kernel.org/stable/c/5c63ad2b0a267a524c12c88acb1ba9c2d109a801","https://git.kernel.org/stable/c/67677050cecbe0edfdd81cd508415e9636ba7c65","https://git.kernel.org/stable/c/7d3232214ca4ea8f7d18df264c3b254aa8089d7f","https://git.kernel.org/stable/c/9d243aff5f7e6b04e907c617426bbdf26e996ac8"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:59:48.811064707+00:00"},"epss":{"cve":"CVE-2022-49059","score":0.00303,"percentile":0.23154,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}